HIV is primarily a sexually transmitted disease, and vaccines which induce mucosal immunity to HIV may offer the best long-term approach to stopping the spread of AIDS. The purpose of this project is to use the SIV/rhesus macaque system to determine if the mucosal adjuvant cholera toxin can be used to elicit mucosal immune responses to SIV antigens. Two rhesus macaques were orally immunized with CT mixed with 1000ug of SIVp55, and 2 animals were orally immunized with CT mixed with 250ug of SIVp55. The animals immunized with CT and high dose antigen made strong systemic immune responses to P55 including antibody, T cell proliferative and T cell cytokine responses to P55. The immune responses in the animal immunized with low dose P55 were weak. The secretory antibody levels in these animals are being assessed. An animal was orally immunized with 1000ug P55 with no CT and the immune responses in this animal are being assessed. This study demonstrates that the mucosal adjuvant CT is effective in rhesus macaques. Future studies will compare the mucosal adjuvant E.coli heat-labile toxin to the results of the CT study. *KEY*Adjuvants, HIV mucosal immunity, SIV antigens